Law enforcement officers check cars at the roadblock near Angeles Oaks during a standoff …

Human remains found in a burnt-out mountain cabin in California have been confirmed as those of alleged cop-killer Christopher Dorner, the local sheriff and coroner's office said.

The 33-year-old was cornered Tuesday after a six-day manhunt in the cabin near the Big Bear ski resort, two hours east of Los Angeles. Authorities in San Bernardino County used dental records to positively identify his remains.

He was believed to have died amid fierce gunfire after SWAT marksmen surrounded the cabin, which was set alight after police threw pyrotechnic tear gas into it. It was not known if he died from gunfire or the blaze.

The ex-Los Angeles Police Department (LAPD) cop went on the run last week after allegedly killing a couple and a policeman, and wounding three people. Another officer was killed and one wounded before the cabin blaze.

Dorner had posted a chilling online manifesto in which he threatened to kill policemen and their families, and blamed the LAPD for treating him unfairly in his sacking in 2008.

The manhunt came to a climax Tuesday in a cabin near the snow-covered ski resort, after Dorner was spotted in a stolen vehicle, and fled on foot after crashing one vehicle and carjacking another.

LA Mayor Antonio Villaraigosa and LAPD chief Charlie Beck meanwhile said authorities were considering whether anyone is eligible for a $1 million reward offered for information leading to Dorner.

The most likely claimants appear to be a couple who were tied up in their cabin by Dorner before he stole their truck, and a motorist who had his vehicle carjacked after the fugitive ex-cop crashed the first stolen vehicle.

"More than 20 jurisdictions and entities are involved in this reward, so all of them will be coming together to collectively determine whether any individual or individuals qualify for it," they said in a joint statement.

"Our personal hope is that the reward will be distributed, but we must follow the rules and respect for the procedures of each entity."

Dorner was first traced Tuesday after he tied up a couple, Jim and Karen Reynolds, in their cabin. He fled in their pick-up truck, but they managed to free themselves and call the police.

"He huddled down beside me and said, 'You're going to be quiet, right? Not make a fuss and let me get away?'" Jim Reynolds, 66, told the LA Times newspaper.

After details of the truck were broadcast to all local authorities, a wildlife patrol officer spotted him and gave chase. But Dorner crashed the truck, and took off in a new car after holding up a passing motorist.

That motorist was Rick Heltebrake, who said Dorner pointed a large assault-type rifle at his head.

"I did not feel like he wanted to hurt me," he told the LA Times. "It was clear I wasn't part of his agenda and there were other people down the road that were part of his agenda.

"Unfortunately, he found them, and now we have one less sheriff's deputy in San Bernardino," he said.

A short time later, with multiple cars in pursuit, Dorner abandoned the car and headed off on foot, toward an empty cabin some distance from the road, before engaging in a shootout that killed one officer and wounded another.

Hundreds of officers swarmed into the area. Footage obtained by CBS television showed lines of armed officers sheltering behind vehicles and trees, watching the cabin.

A long barrage of apparent gunfire can be heard on dramatic video footage of the standoff, as officers look on, taking occasional aim. As they watch, smoke begins to emerge from the cabin, which was eventually engulfed in flames.